Folding knife



FIG. 1 is a left-side elevational view of a folding knife, the right-side elevational view being a mirror image thereof;

FIG. 2 is a top view thereof;

FIG. 3 is a bottom view thereof;

FIG. 4 is a front elevational view thereof from the point end of the folding knife; and,

FIG. 5 is a back elevational view thereof from the butt end of the folding knife. 

The ornamental design for a folding knife, as shown and described. 